OTTAWA — Open source software is playing a growing role in telephony, and getting the attention of major equipment suppliers, but there is still an element of “buyer beware” in the use of open-source telephony technologies.

Those were the key messages from a panel on the subject at the inaugural Voice 2.0 conference here Monday.

Open source is an ideal way for companies to handle development projects that have to be done but don’t directly affect customer satisfaction, argued Mike Milinkovich, executive director of the Eclipse Foundation, an open source software community. According to Milinkovich, that’s about 80 per cent of software development. “The whole idea behind open source is to go get the stuff that your customers don’t care about and get it for free,” he said.

That’s what Mark Spencer was doing when, as the founder of a Linux support company about seven years ago, he decided he didn’t want to pay for a private branch exchange (PBX). So he set out to write his own software to run the company’s phone system. That software became Asterisk, probably the best known example of open-source telephony software today.

Asterisk is not the only open-source software or even necessarily the best, noted Jim van Meggelen, president and chief technology officer of Core Telecom Innovations Inc., a Toronto-based telecom products and services provider, though it is the “media darling” at the moment. Van Meggelen said another product, SIPx, is more robust. There are a few other open-source products on the market, at least one predating Asterisk.

And while open source technology can help reduce costs, it doesn’t make telephony free and it offers no guarantee of quality. During the discussion, one audience member said he has had several clients adopt Asterisk and then get rid of it in a year or so because they found it did not scale well. Van Meggelen agreed. “Asterisk is not designed to scale,” he said. “Asterisk was originally designed because somebody was too cheap to buy a telephone switch.”

At the same time, he said, “if you’re willing to sit down with it and learn it, you can do unbelievably complicated things with this system.”

It’s a question of buyer beware, Milinkovich said. “Open source is not a panacea.”

Van Megellen said the challenge with open-source software, and particularly early open-source software, is that you are responsible for making it work. Wai Seto, senior technology expert at Nokia Corp., said anyone adopting open-source telephony needs to do some homework and if necessary take on the task of fixing problems and returning the improvements to the open-source community. “We don’t just pick it and start using it,” he said.

But the presence of Seko and Chris Hobbs, senior manager of system architecture at Nortel Networks Corp., on the panel showed that open-source software is now on the radar screens of major telecom equipment suppliers. Both Nortel and Nokia are working with open source software internally. Nokia has incorporated open-source components in its new 770 home mobile appliance. Hobbs said Nortel has developed a model for ranking corporate acceptance of open source, ranging from denial to the point where open source becomes an intrinsic part of the business process.

And while he acknowledged that the quality of open source products varies, van Meggelen took issue with the perception that open-source software is the work of hobbyists programming in their spare time. “Something like 90 per cent of the Linux kernel developers are full-time paid employees of large companies,” he said, arguing that corporations are using the open-source model to do “shared-risk, shared-cost development.”

Open source and open standards are “a match made in heaven,” Hobbs added. “You first innovate in open source, and then once you’re got an implementation that’s demonstrated to work, then you turn that into a standard.”